The enzyme cyclic GMP-AMP Synthase (cGAS) catalyzes the synthesis of cyclic GMP-AMP (cGAMP) from ATP and GTP in the presence of DNA. This cGAMP then functions as a second messenger that binds to and activates STimulator of INterferon Genes (STING). The activation of IRF3 and the NF-κB signaling by this pathway results in the production of cytokines and type I interferons, which triggers an innate immune response to bacterial or viral infection. Genetic mutations that alter the balance of this pathway may result in an increased activation of the STING pathway, resulting in autoimmune and inflammatory diseases. For example, a loss of function mutation of TREX1 exonuclease, which digests DNA, can result in an accumulation of self-DNA in the cytosol, leading to excessive levels of cGAMP produced by cGAS and elevated expression of interferon induced genes in this pathway. Mutations in TREX1 are associated with systemic inflammatory diseases such as Aicardi-Goutieres Syndrome, familial chilblain lupus and systemic lupus erythematosus. Trex−/− mice were shown to exhibit autoimmune and inflammatory phenotypes which are eliminated with genetic deletion of cGas in these mice (Gao et al., PNAS 112(42):E5699-705, 2015; Gray et al., The Journal of Immunology 195:1939-1943, 2015). Thus there is a need for inhibitors of the cGAS/STING pathway for the treatment of a variety of diseases.